A novel experimental approach based on a toroid Cavendish balance is used to evaluate the product of photon mass squared and the ambient cosmic magnetic vector potential . The method is based on the energy density of the vector potential in the presence of photon mass, not on measurement of the magnetic field. The experiment discloses , with as the characteristic length associated with photon mass. Consequently, if the ambient magnetic vector potential is due to cluster level fields, . If we conservatively use galactic fields prior to a reversal, then , a figure still superior to that derived from the Jovian magnetic field.
- Received 2 June 1997
- Revised 11 December 1997
- Published in the issue dated 2 March 1998
© 1998 The American Physical Society